Effect of Impella 5.5 on Preexisting Functional Mitral Regurgitation in Patients with Heart Failure-Related Cardiogenic Shock.

Background: Heart failure-related cardiogenic shock (HF-CS) is increasingly common. Moderate/severe functional mitral regurgitation (FMR) is commonly seen in patients presenting with decompensated heart failure and is associated with worse outcomes. Percutaneous mechanical circulatory support devices are increasingly used to provide hemodynamic support for ongoing CS. There is no description of the impact of Impella device on hemodynamic response when used in combination with preexisting FMR. Methods: Retrospective review of patients aged ≥18 years, who underwent Impella 5.5 implant for HF-CS, and who had a transthoracic echocardiogram performed pre- and post-Impella. Results: Of 24 patients, 33% had moderate-to-severe/severe FMR, 38% had mild-moderate/moderate FMR, and 29% had trace/mild FMR on pre-Impella transthoracic echocardiogram. Additional right ventricular assist device was simultaneously inserted in 3 patients, of whom 1 had severe, 1 had moderate, and another had mild FMR pre-Impella. Despite maximally tolerated Impella unloading, 6 patients (25%) had persistent moderate-severe/severe FMR, and 9 (37.5%) patients had persistent moderate FMR. Overall, however, there was a decrease in central venous pressure, pulmonary artery diastolic pressure, serum lactate, and vasoactive-inotrope score at 24 ​hours post-Impella, and survival was high at 83%. Conclusions: In a retrospective cohort of patients admitted with HF-CS who underwent Impella 5.5 implant for hemodynamic support, Impella did not seem to acutely ameliorate FMR severity. Despite this, there was a significant improvement in hemodynamic response at 24 ​hours post-Impella. In carefully selected patients, especially those with isolated left ventricular failure, Impella 5.5 may provide adequate hemodynamic support even in the presence of higher severity FMR.